Abstract: From the angle of reducing searching region, strengthening convergence and shortening calculating time, the simulated annealing idea is introduced into the genetic algorithm to solve the optimal sequential casing problem of less-than-carload freights in containers. The specific process for realizing the algorithm is expounded, including coding, fitness function calculation, genetic operation, neighborhood selection and temperature reducing methods,etc. Practical numeric calculation shows that the algorithm is superior to the old resolutions.